Electronic biomedical devices such as pacemakers, defibrillators, left ventricular assist devices (LVADs), cochlear implants, diaphragm pacemakers, artificial retinas, glucose sensors, insulin pumps, and neuromuscular stimulators are significantly improving both the length and quality of life for millions of people. New implantable devices are under development to treat a myriad of disabilities and ailments including spinal cord paralysis, epilepsy, diabetes, blindness, and deafness. Power sources used for many such portable devices may require large current drains, and thus require relatively large size batteries for extended use. Additionally, life-critical implantable medical devices require ultra-reliable power sources.
It has been widely taught that implantable, self-sufficient energy sources are impractical for high-power devices such as circulatory assist devices (See e.g. U.S. Pat. No. 4,665,896 to LaForge et al.). While implantable battery technology has improved significantly in recent years, it remains necessary to provide external energy sources for such high-power devices. Since artificial hearts, LVADs, diaphragm pacemakers, ventilators, and the like must have 100% reliable power sources and back-up power, these devices require that the patient either remain tethered to a fixed power source, or remain close to a fixed power source for frequent recharging of a portable power source. This severely impacts the patient's quality of live by restricting mobility.
Several devices have been developed to provide portable power suitable for various non-medical uses. For example, U.S. Pat. No. 5,211,321 to Rodriguez describes a battery and equipment vest containing batteries suitable for powering photographic equipment. Similarly, U.S. Pat. Nos. 5,929,597 and 6,106,971 teach wearable power sources for cordless devices such as power drills. U.S. Design Pat. No. D475,680 illustrates the ornamental appearance of a wheeled battery cart containing an air compressor, light, and inverter for powering a variety of electrical devices. None of these provide power for implanted medical devices.